1. Field
Aspects of embodiments according to the present invention relate to an organic light emitting display device and a method of manufacturing the same.
2. Description of the Related Art
In general, a flat panel display device may be categorized as a light-emitting type display device or as a light-receiving type display device. Light-emitting type display devices include flat cathode ray tubes, plasma display panels, electroluminescent display devices, light emitting diode display devices, or the like. Light-receiving type display devices include liquid crystal displays (LCDs) or the like. Among these display devices, electroluminescent display devices are expected to become next generation display devices due to their wide viewing angle, high contrast, and fast response speed. An electroluminescent display device may be an inorganic electroluminescent device or an organic electroluminescent device (e.g., organic light emitting display device), according to a material that forms an emitting layer (EML).
In this regard, the organic electroluminescent device is a self light-emitting type display device that emits light by electrically exciting a fluorescent organic compound. The organic electroluminescent device can be driven at a low voltage, can be made thin, and can solve problems related to a wide viewing angle and fast response speed of an LCD. Thus the organic electroluminescent device is expected to become a next generation display device.
The organic electroluminescent device includes an EML formed of an organic material between an anode electrode and a cathode electrode. In the organic electroluminescent device, when a positive voltage and a negative voltage are applied to the anode electrode and the cathode electrode, respectively, holes that are injected from the anode electrode move to the EML via a hole transport layer (HTL), and electrons from the cathode electrode move to the EML via an electron transport layer (ETL), so that the electrons and the holes are recombined in the EML to generate excitons.
When the excitons are changed from an excitation state to a ground state, fluorescent molecules in the EML emit light that may form an image. In the case of a full color type organic electroluminescent device, a full color spectrum is realized by having pixels that respectively emit red (R), green (G), and blue (B) colors.
In the organic electroluminescent device, a pixel defining layer (PDL) is formed at edges of the anode electrode, a predetermined aperture is formed in the PDL, and then the EML and the cathode electrode are sequentially formed above a portion of the anode electrode that is externally exposed due to the aperture.